The importance of moisture feedback between continental precipitation and evaporation, referred to as moisture recycling, is still under debate. Most of the research in the past focused on the contribution of recycling to precipitation within a certain region only. This paper clearly distinguishes between different definitions of moisture recycling. This allows us to study the complete process of continental moisture recycling. In addition to identifying how much of the precipitation originates from
continental sources, a new definition is used to identify regions which are major moisture suppliers for continental precipitation.
An accounting procedure based on ERA‐40 reanalysis data is used to calculate moisture recycling ratios. As such, this paper derives new information from existing data. It is estimated that on average 38 % of the continental precipitation has continental origin and that 52 % of the continental evaporation returns as precipitation over continents. This paper demonstrates the important role of topography in the Andes and the Tibetan Plateau where regional moisture recycling is a key process. The Amazon and the Congo are identified as very important regions for sustaining continental precipitation. It is also demonstrated that moisture recycling from the Eurasian continent is the major supplier of the fresh water resources of China.

Introduction:
The addition of vegetation to the banks urban drainage channels is an increasingly common measure for improving water quality, enhancing ecological health, and improving aesthetic appeal. An in-stream wetland concept is proposed for channels in Singapore to just that, but faces a major challenge in that high flow rates during storm events will increase the risk of damage to the vegetation.
Problem definition:
In high-flow situations, flow around the vegetation causes a region of turbulent shear to develop along the interface between the vegetation and main, open-channel flow. This is expected to impact the hydraulic resistance in the channel and the drag forces experience by individual plants, especially those nearest to the interface. For design it is important to understand the effects of this turbulent shear on drag to optimize design to limit upstream flooding risk and assess the risks of damage to plants.
Research:
The aim of the research was to increase understanding of the effects of lateral, turbulent shear on the channel resistance and forces experienced by individual stems in a uniform patch of vegetation. A patch of uniform vegetation was modelled by an array of rigid cylinders in an experimental flume. Measurements of the flow field and the drag forces on individual cylinders were recorded. Using this data, answers to the following questions were found:
1) What is the effect of lateral turbulent motion on channel resistance?
2) How do drag forces on individual stems vary spatially over the patch and in time, with special attention to local maximums?
3) What is the effect of lateral turbulent motion on fluctuations in the stem drag force?
4) What are the implications for estimation of the mean and maximum stem drag forces?
Results:
Analysis of the experimental results revealed the following:
1) The presence of a lateral shear layer significantly increased channel resistance, by 175% when compared to similar conditions when the shear layer was not allowed to develop.
2) Drag forces on stems mirrored the velocity distributions in both time and space, showing both higher mean and maximum values near the interface between the stem array and open channel.
3) Similar periodicity in the velocity and force signals gave evidence of coherent, turbulent structures as the primary means of momentum transport across the vegetation interface. This motion causes a sweep-ejection pattern in the flow at the interface with a net flux of momentum towards the vegetation, resulting in a skewed distribution of stem forces towards higher extreme values.
Conclusions and recommendations:
Lateral turbulent shear is an important factor in both the channel resistance and stem drag forces in a partially vegetated channel. Coherent structures at the vegetation interface were determined to be the main factor in stem force distribution within the region of shear. The mean stem force can be derived directly from the mean velocity given adequate assumptions of the vegetative drag coefficients. A conceptual model was developed to describe the maximum force in the vegetation patch as a function of the mean velocity at the vegetative interface and a fraction of the difference in velocities between the vegetated and open channel sections.

Introduction
Different water resources are shared among neighbouring nations worldwide, as water does not recognize any (political) boundaries. This fact has led to conflict and cooperation between neighbouring states over the management of such water resources. To manage these resources in a way that it prevents conflict and promotes cooperation, a wide range of expertise is required. It is the objective of this study to investigate the possible contributions that water experts can bring to the promotion of water cooperation. These objective was achieved by a combinations means of literature study and interviews.
Water conflict and cooperation
It was identified that the causes of conflict and cooperation over a shared water resource can be grouped into two dimension, drivers and indicators. Drivers are events over shared water resources that generate potential conflict. While indicators are factors that strongly-influence whether the potential conflict will become an actual conflict, or even become an actual cooperation.
Results
Water experts can contribute to the promotion of water cooperation by influencing drivers and indicators. These contributions can diminish, or even, counteract the potential conflicts generated by the drivers. Also, they can create a more cooperative indicators. These contributions include:
• To open and maintain communication lines;
• To raise public awareness;
• To build confidence;
• To exchange and jointly collect data;
• To develop and propose potential solution;
• Act as an independent party;
• Capacity building;
• To inform decision makers.
In order for these contributions to effectively impact the drivers and indicators, the water experts need to overcome barriers that may dampen the positive impacts of their contributions, or may even cause counterproductive impacts. Such obstacles range from the ones that are inevitable, attached to the complex nature of the water conflict and are beyond water experts’ grasp, to those that are avoidable. Some of such barriers are:
• Insensitivity to political and social context;
• Inter-disciplinary and inter-level communication;
• Different analysis method;
• Credibility of water experts.
Conclusions and recommendations
To overcome those barriers water experts are recommended to stay modest, closely collaborate with experts from other fields and to give extra effort on understanding the local public, the decision makers and the non-technical aspect of the issue. By doing so the (technical) solution that water experts will become more acceptable by those parties. Also, this will enable water experts to see whether their involvement will lead to an equal (and desirable) cooperation for all riparians.
Finally, it recommended for universities, as the preparer of the future water experts, to try to make their students realize that in order to be effectively and ethically involved in a transboundary water management, and to promote water cooperation, having the technical knowledge is not enough. Further, universities also advised to provide supporting training upon the request of the future water experts.

Calcium carbonate pellets are produced as a by-product in the softening process. In The Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high potential market segments such as paper and glass.
Earlier work showed that it is technologically possible and in some cases economically feasible to replace sand grains with commercially available calcite grains obtained from limestone (e.g. in Italy or Germany). ). In order to further increase sustainability by reduction of transport, it might be possible to grind and sieve the pellets and reuse this grinded Dutch calcite as seeding material for pellet softening process.
The goal of this research was to determine the possibilities of the use of grinded Dutch calcite as an alternative for the use of garnet sand as seeding material in the pellet softening process.
A comparison between grinded calcite and garnet sand is made based on the five key performance indicators (K.P.I.’s): quality, quantity, costs, reliability and sustainability. Pilot scale tests were conducted at Weesperkarspel (Waternet) during the winter period. The produced calcite pellets were dried, grinded and sieved calcite as seeding material (0.5 mm) by grinding and sieving the Dutch calcite pellets (1 mm). The produced calcite grains were applied as seeding material in a fluidized bed softening reactor (∅ = 30 cm; height = 6 m; velocity = 60-80 m/h). The effect on sustainability was based on a life cycle analysis (LCA) performed in SimaPro. An FMECA was carried out to identify possible risks failures for the fullscale implementation.
The grinding and sieving experiment showed that an overall yield of 40 % of grinded calcite pellets with a diameter of 0.4 – 0.6 mm, could be reached. The pilot pellet softening experiments showed that the softening performance of the Italian calcite and the grinded Dutch calcite scenario, in terms of water quality parameters (total hardness, turbidity, pH, NaOH dosage), were comparable from the garnet scenario. The results of the modeling in Stimela showed comparable results with the pilot plan experiments.
The LCA concerning the Weesperkarspel plant and its pre-treatment showed a score of 215,250 EcoPoints (Barrios et al., 2008). The scenario of grinded calcite seeding material results in a decrease of about 3824 EcoPoints, 1.8 %, due to reduced transportation of garnet.
Usage of grinded pellets in Dutch industries (compared to imported calcite) results in a total decrease of 10.640 EcoPoints, 5%, mainly caused by the reduced transportation.
The business case showed that costs of the seeding material will be lower due to the reuse of the grinded pellets as seeding material. Due to the improved pellet quality the pellet turnover will increase. The worst-case scenario showed a possible cost reduction for the WPK plant of € 38,000 (1.8%). For both treatments of Waternet a costs reduction of € 120.310 (1%) can be achieved.
The scenario study for the full-scale implementation showed that a transition, of all eight reactors at the treatment facility of WPK, from garnet sand to calcite as a seeding material introduced the fewest risks for water quality and reliability.
The FMECA showed that for the full-scale implementation the hygiene of the seeding material is an important factor.

A continuous population growth and increasing energy demand combined with depleting traditional energy reserves puts a pressure on conventional methods of electricity generation. The desire and ambition to create a more sustainable society paves the way for the ‘renewables’. Hydropower or Hydroelectricity already plays a significant role in global energy production, especially the large hydropower plants with giant reservoir lakes. The contribution of small and micro hydropower however is not really clear. Smaller hydropower plants have some advantages compared to larger plants in terms of sustainability, local benefits and electricity supply in remote areas. The exact location of potential hydropower plants is mostly unknown and the total potential of all combined hydropower capacities for a certain region has not been evaluated as well. This research aims to give insight in the potential of hydropower for a specific region and distinguishes micro, small and large hydropower.
In order to evaluate the global hydropower potential a systematical method has been developed to simulate input data and check whether there is hydropower at a specific location. The approach is based on a distributed model and raster data. The world is divided into cells with a 3” (three seconds or 92m near the equator) resolution. For each and every cell the hydropower capacity is systematically determined. In order to do this the two basic components for hydropower, head and discharge need to be evaluated for each cell. The discharge is calculated with help of the HydroSHEDS’ DEM and DIR datasets combined with the GRDC Runoff fields’ dataset. Based on the Flow Direction, derived by HydroSHEDS a ‘runoff weighted’ flow accumulation was executed to obtain the accumulated runoff for each cell which is converted into discharge. The head is calculated with the cell size and slope within each cell. The slope was derived from a global 3” DEM which has been modified with the discharge map to obtain a RiverDEM which forms the basis for the slope calculation. Hydropower is calculated within each cell using the Input Variables ‘turbine efficiency’, ‘minimum discharge’ and ‘minimum head’.
The results are filtered into micro, small and large hydropower locations. To give insight in the total hydropower capacity for a specific region the total hydropower is accumulated per category for a region of 0,50 degree times 0,50 degree (about 50 km2). The final output is a global map of accumulated hydropower per category with a resolution of 0,50 degree.
It is computed that the total gross theoretical hydropower capacity potential is about 20TW with Asia as the largest contributor. Large hydropower accounts for over 80% of this potential while micro hydropower only accounts for 2% of the total potential capacity. This paper demonstrates new, insightful images on spatial hydropower distribution, showing that Colombia, Myanmar, Indonesia and Madagascar are examples of areas with extensive hydropower potential. Overall this study provides a consistent global modeling approach that allows both a quick comparison of hydropower potential between regions as detailed information on a specific hydropower location.

Since several decades organic micro pollutants (OMPs) have been detected in natural waters. Although appearing in very low concentrations (nanograms to micrograms per litre or even lower), the presence of more than 100.000 registered chemical substances in the European Union, of which 30.000-70.000 are in daily use, is a major reason for concern. Due to their persistent character the OMPs remain longer in the water cycle and can be transported over a longer distance than other pollutants. Current treatment facilities are not designed to remove those compounds, which causes them to end up in the environment and even in drinking water. The current problems on OMPs in the water cycle are not that the concentrations present in the water cycle are too high to guarantee the safety of drinking water, but are the long-term effects of these concentrations, the increase in concentrations (due to changing circumstances) and the unknown effect of OMPs in mixtures with other OMPs. In order to find a solution to this problem this project focusses on the following question: What is the most sustainable, applicable and cost-efficient strategy to reduce concentrations of selected micro pollutants in surface water and drinking water in the Netherlands?
In this project various strategies to reduce the concentrations of OMPs are composed and scored by a Multi Criteria Analysis (MCA). The best strategy is tested on two case studies to see the influence of the strategy on the concentrations. The future situation regarding the emission of OMPs and discharge of river water is also taken into account. Whether the strategy is effective is determined based on limits of concentrations of OMPs.
The scope of the project is on drinking water extraction areas in the Netherlands. Firstly a literature study on current European and Dutch legislation and policy, future trends regarding population growth, consumer behaviour and climate change and the presence and behaviour of target compounds in the water cycle is conducted. Based on the Deltascenarios two future scenarios regarding emission of OMPs, river discharge and precipitation are selected: REST and STEAM. Scenario REST is a scenario of economic stagnation with moderate climate change. In scenario STEAM both the economic situation and climate change increases. Later in the report these scenarios are used to test the best strategy on, which reduces the concentrations of OMPs in the water cycle. Dutch limits on OMPs in the water cycle only exist for a few compounds. For other compounds target values of other organisations are used. The found limits and target values are in the order of 0.1-1.0 μg/L. The target compounds are selected based on an analysis of relevant compounds, which results in a limited number of compounds to elaborate on. Persistence of the compounds and availability of measurement data are important criteria in this analysis. The selected target compounds are carbamazepine, metformin, sulfamethoxazole (pharmaceuticals), iopromide (X-ray contrast agent), acesulfame-K, caffeine (domestic tracer compounds), MTBE (industrial chemical), AMPA, bentazone, glyphosate and N,N-DMS (pesticides). In surface water concentrations of the selected compounds between 0.025 and 83 μg/L are measured. Found removal efficiencies in WWTPs and DWTPs vary between 0 and 98%, highly depending on the type of OMP, the used treatment techniques and the composition of the influent.
Different strategies with different approaches within the water cycle are discussed, which are divided in source approach (use), mitigation approach (emission) and end-of-pipe approach (drinking water). Source approach:
1. Green pharmacy
2. Awareness in use and prescription
3. Legislation and policy
4. Green agriculture, greenhouse farming and cattle breeding
Mitigation approach:
5. Separate collection of urine
6. Decentralised collection of wastewater in residential areas
7. Decentralised collection of wastewater in hospitals
8. Improvement of wastewater treatment plants
End-of-pipe approach:
9. Improvement of drinking water treatment plants
A MCA and sensitivity analysis are used to present the best strategy that is well balanced between all aspects of the water cycle and its users and which is sustainable, applicable, cost-efficient and which functions within European and Dutch legislation. The strategies are scored based on an expert judgement of the expert panel. The best two strategies are applied on water and mass balances of the two case studies to see the impact of the strategies. The first case study is the Bethunepolder between Amsterdam and Utrecht. This is a groundwater system. The second case study is the IJsselmeer area at Andijk, which is a surface water system. Both areas are partly fed by water originating from the river Rhine and serve as a drinking water extraction area. A water balance and, by multiplying the discharges by the measured concentrations, a mass balance of OMPs is composed. The results from the mass balances show whether or not the strategies are sufficient to decrease the concentrations to below the limits. Finally, a comparison between the two types of water systems (groundwater and surface water) is made.
The MCA results in a highest score for the strategy ‘legislation and policy’. However, this strategy only holds when incorporating other measures to reduce the emission of OMPs into the water cycle (implementing stricter regulations results in the need for solution at the use or emission of OMPS, WWTP or DWTP). For this reason also a second best strategy is determined. Strategies 1, 2, 4, 8 and 9 are in the same range and score moderately, where strategies 1 and 2 score higher than the remaining three strategies. Although without a big difference with the third best strategy, the second best strategy is ‘green pharmacy’. All strategies with (de)centralised collection and treatment of urine or total wastewater score poor, due to a poor score on all three aspects: sustainability, applicability and cost-efficiency. Although, the systems in the two case studies are both partly fed by the river Rhine (via the groundwater and via the river IJssel), the measured concentrations and exceedance of limits and target values are not the same. In the Bethunepolder the calculated concentrations exceed the limits for six compounds, while none of the measured concentrations exceed the limits. In the Andijk case the calculated concentrations of five compounds exceed the limits, while for the measured concentrations these are only three substances. The future scenarios regarding the emission of OMPs and the discharge of river water are not influencing the (non-) exceedance of the limits. After applying the strategies on the models in the Bethunepolder case concentrations of most compounds decrease to below the limits, where this decrease is in the Andijk case not enough to go below the limits. For both case studies the results show that ‘legislation and policy’ is a better strategy, because concentrations of all compounds are reduced, while for ‘green pharmacy’ only the concentrations of pharmaceuticals decrease.
From these results it is concluded that ‘legislation and policy’ is the most sustainable, applicable and cost-efficient strategy to reduce concentrations of selected compounds in surface water and drinking water in the Netherlands. With this strategy governmental regulations regarding the emission of OMPs into the water cycle are improved. Comparing the two case studies with each other it can be concluded that in a groundwater driven system the influence of OMPs seems to be less acute than in a surface water system. However, in the groundwater system the effects of the presence of OMPs will be noticeable after a longer period, which makes this system more unpredictable and it takes more time till measures are resulting in a decrease in concentrations. In this project the MCA is performed without exact numbers for the criteria ‘sustainability’, ‘applicability’ and ‘cost-efficiency’. Further research on these aspects and the addition of more criteria improves the reliability of the MCA and thus of the winning strategy. Regarding the composed models of the case studies more attention needs to be paid to the assumptions on mixing and decay. In a system with high residence times (like the groundwater system of the Bethunepolder) decay could play an important role in the modelling.

Introduction
For several years it is known that as a consequence of climate change rain patterns will change in the future. Winters are becoming wetter and summers are becoming drier. Especially in summer period extreme rainfall will more often occur. Extreme rainfall may lead to ' water in the street ' and 'flooding '. ' Water in the street ' is defined as a water level that is higher than the local ground level or drain cover level. ' Flooding ' is defined as ' water in the street ' where nuisance to local residents and users of the public space occurs.
When flooding takes place, there is the possibility that victims report this to the administrators and/or owners of the public space (province, local municipalities and water boards) or civil society organizations. It is also possible that flooding results in people submitting insurance claims.
Research
Data registered in registration systems is often incomplete or unusable. The registered data from three municipalities has been studied and is used to investigate the manner in which the current registration methods can be improved, so that the data collected (building blocks) better contribute to a more efficient management of the sewer system. The efficiency of the report registration procedure is determined by the data quality of the building blocks, the registration system and the person who evaluates and uses the registered information. A notifier can pass the message on through a number of channels. The channels are the "inputs" that make it possible to reach the public authority. The following (main) channels are differentiated:
1. Channel telephony
2. Channel internet (e-form)
3. Channel email
4. Channel mail
5. Channel desk
Conclusions and Recommendations
When all notifications (100%) are registered by the channel desk this results in the highest efficiency, followed by the channel internet. Since it is not realistic that all contacts take place through the channel desk, because many municipalities will reduce the contact by desk in the future, the use of the e-form will become more and more important. A well developed, easy to use, comprehensive and reliable e-form is essential in the future.
Damage claims, arising from a bad or slow handling, can be prevented if a proper registration system is used (System), the registration procedure is well organized (procedure) and the user of the information uses the data properly (man). The risk of damage claims is high as the efficiency of the registration process is low or the information of the registration system is used not correct or incomplete.
A practice situation, in which the data quality parameters of the channel internet is at least equivalent to the current parameters of the channel desk and an increased use of the internet channel, is preferred in future.

This research evaluates the potential of thermal infrared (TIR) remote sensing to determine and continuously monitor the horizontal water temperature distribution of inland surface water bodies. Usually, monitoring temporal and spatial variability of surface water temperature takes place by measurement networks of in-situ gauges, but these networks are often limited by sparse sampling in both time and especially space.
For these and other reasons (e.g. relatively cheap, easy, and fast) the use of remote sensing in water management studies and practices has increased. By remote sensing in the TIR spectrum the TIR radiation leaving from the top surface water layer (< 0.1 mm) is measured, which can be used to determine the radiant water temperature distribution in the horizontal plane. This horizontal radiant water temperature distribution can be used as supplement to in-situ kinetic temperature measurements. It is however necessary to first evaluate the accuracy and precision of the remotely sensed water temperatures. Therefore, the goal of this study is to determine how and with what accuracy and precision TIR radiant water temperature measurements (Tremote) can be used as an approximation for the horizontal distribution of the kinetic water temperature, based on comparisons of Tremote with in-situ kinetic water temperature measurements (Tin-situ).
The criteria used in this study to determine the accuracy and precision of Tremote is by means of comparison with Tin-situ, which are usually taken at a certain depth in the water column. Tremote represents a pixel value, which is thus compared with a point measurement of Tin-situ. The bias (Tremote – Tin-situ) statistics are indicative for the obtained accuracy and precision.
In this study Landsat 7 ETM+ images measured in the thermal infrared spectrum (λ = 8-14 μm) are used for water temperature determination of Tremote (by means of the inverse of Planck’s Law), together with Landsat 7 ETM+ images measured in the visual and near infrared spectrum for water detection of inland surface water bodies. The effects of emissivity; atmospheric absorption, emission and scattering; and surface effects and thermal stratification are evaluated and, if possible, corrected for. Uncertainty contained by the Landsat 7 ETM+ instrument has been taken into account by means of applying a 95% confidence interval over the obtained surface water body. Reduction of thermal pollution by land-originating TIR radiation of radiant water temperatures is well established by such a 95 % confidence interval water body.
The correction for atmospheric circumstances took place by means of the web-based Atmospheric Correction Parameter Calculator, ACPC (see http://atmcorr.gsfc.nasa.gov/), which makes use of the MODTRAN radiative transfer model. Obtained results have been verified by means of a newly derived atmospheric correction algorithm for Landsat 7 ETM+ TIR images, developed with use of the MODIS In-Scene Split Window Method. For clear-sky images, on which this study focuses, the uncertainty contained by the atmospheric correction is up to ±0.8 °C inland, which can increase up to ±1.5 °C near the coast. Coastal uncertainty of the atmospheric correction is larger because of larger coastal atmospheric gradients (mainly of water vapour), which is difficult to correct for.
The emissivity of water approaches that of a black body (ε = 1), but is usually 1 to 2 % lower. This causes a reduction of up to 1 °C of the established radiant water temperature, but introduces an uncertainty of up to ± 0.5 °C.
The surface effects and thermal stratification are influenced by many factors and processes which are difficult to address. The combined result of the surface effets and thermal stratification lead to an uncertainty in winter and summer of ±1.6 and ±3.2 °C, respectively.
Overall, this study concludes the best procedure to approximate the horizontal kinetic water temperature distribution of inland surface waters with Landsat 7 ETM+ TIR images makes use of a 95% Confidence Interval Water Mask, and an Emissivity and Atmospheric Correction.
The accuracy and precision levels of the horizontal water temperature distribution display an average bias of 1.5 °C with σ = 1.5 °C and SE = 0.1 °C. Tremote tends to nearly always over-predict Tin-situ. Using the 95% Confidence Water Mask to avoid thermal pollution of water pixels by land (sub-pixel heterogeneity), rivers with a width less than 120 m cannot be well resolved from the ETM+ images anymore. Furthermore, no physical relation could be derived between Tremote and Tin-situ. The numerous and complex processes that together affect the measurement of Tremote and its agreement with Tin-situ, combined with the issue of the scale difference between Tremote and Tin-situ, make it difficult to derive a (physical) relation or formula that connects Tremote to Tin-situ. The seasonal influence, expressed by a difference between winter and summer, could be captured by means of the statistical analysis. During winter, Tremote over-predicts Tin-situ on average by 0.8 ° with a bias spread of σ = 0.8 °C and SE = 0.2 °C. During summer, Tremote over-predicts Tin-situ on average by 1.8 ° with a bias spread of σ = 1.6 °C and SE = 0.2 °C.
The bias statistics of the obtained horizontal Tremote distribution and the statistical seasonal relation between Tremote and Tin-situ can be used as an approximation for the horizontal kinetic water temperature distribution. Based on the results in this study and the difficulty to establish a more direct relation between Tremote and Tin-situ, the proposed systematic correction becomes: in winter Tremote - 0.8 and in summer Tremote – 1.8. The bias spread statistics (σ and SE) form a first and reasonable quantification for the precision and uncertainty contained by the obtained approximation.
It is recommended to attempt to reduce the uncertainties contained by approximations obtained in this study by further research. Research towards a better Atmospheric Correction, which especially accounts for local surface conditions and the spatial variations in atmospheric circumstances, could mean a major improvement for the remotely sensed water temperature approximations.
Other research to improve the approximations of horizontal kinetic water temperature distributions by Tremote is to assess the thermal stratification and the surface effects. To better understand the thermal water body processes and the skin effect, improving our insight in the relation between kinetic water temperature in the water column, kinetic water temperature at the surface (water depth 0 m) and the TIR radiant surface water temperature measured locally would help. This improved insight would also help to reduce the uncertainty of remote sensing measurements.
It is also recommended to investigate and improve the operational abilities of remotely sensed water temperatures. A main practical constraint is the time interval by which images of the same location are generated by the Landsat 7 satellite: 16 days. Therefore, to operationalize space-borne remote sensing of water temperatures for daily water management practises it is highly recommended to include more satellites with a TIR spectral channel. Another practical recommendation is to optimize the time of ETM+ image acquisition and processing. With NASA currently requiring 1-3 days to process the images to L1T process level, it must be carefully decided for what purposes the water temperature information can be used.

Directly coupling renewable energy to reverse osmosis may be the most cost effective solution to supply potable water to remote and isolated areas that lack infrastructure and safe drinking water. These systems do not use batteries but rather operate only when sufficient energy is available and store any excess energy as water. Since reverse osmosis membranes are designed to be operated for continuous periods under constant power, it has been unclear how the fluctuating operation will affect the performance of the membranes.
In these experiments, a small-scale reverse osmosis unit (maximum production 8 m3/day) was set up in the laboratory to continually recycle and treat a reservoir of artificial seawater (32 800 mg/L NaCl). The power of the high pressure pump feeding the reverse osmosis membranes is fluctuated corresponding to inputs of real wind data entered through an automated computer system. Measurements of pressure, permeate production and conductivity were continually recorded and used to determine if there were changes in the membrane permeability coefficient and salt rejection of the membrane resulting from fluctuating operation.
After more than 650 hours of fluctuating operation, no deterioration of reverse osmosis membrane performance was observed.

Hydraulic roughness is a key factor in modeling open channel flow. The frictional effects of roughness elements are generally parameterized by a roughness coefficient, representative for the roughness of a grid cell in a model. Bed roughness can be very heterogeneous in practical situations. Especially in floodplains, the roughness height can differ an order of magnitude over a small distance. This roughness heterogeneity impacts the shear stress distribution and the effective friction exerted on the flow. Previous research showed that the effective friction was 20% more than the theoretically weighted average value (Jarquín, 2007) in a flume with a parallel smooth-to-rough bed. Another calculation showed even 80% additional effective friction (Jarquín, 2007; Vermaas et al., 2007). New measurements and a detailed Large Eddy Simulation model described in this report were used to investigate the underlying mixing layer processes and the corresponding development length scales. This may provide the basis to parameterize roughness heterogeneity.
Measurements in a developed flow over a parallel smooth-to-rough bottom show a secondary circulation in vertical planes across the flow. This circulation causes a transverse momentum transport from the smooth to the rough side. The momentum transport by this mechanism has nearly the same order of magnitude as the transverse momentum exchange by turbulent mixing. The transverse momentum exchange enhances the effective friction. An example with a 2D model shows that this can not explain the entire increase in effective friction; additional friction is probably also caused by extra turbulence production near the smooth-to-rough interface, and bed shear stress in the spanwise direction.
In the transition from a uniform flow to a compound flow over parallel roughness lanes, transverse volume transport occurs mainly in the first 4 meter (twice the width of the flume), with a maximum velocity at the start of the parallel roughness section. The development length of the velocity profiles can be scaled to the depth of flow. The vertical profiles outside the mixing layer develop in about 25 times the water depth; the mixing layer at mid depth in about 50 water depths. The secondary circulation was estimated to be fully developed after 80 water depths, but has already a significant momentum transport at half of this distance. Furthermore, the depth averaged transverse mass transport causes a gradient in the advected longitudinal momentum and therefore the water level slope is even more increased above the start of a parallel rough bottom.
As a typical example of repetitive changing roughness, the flow over a roughness pattern resembling an elongated checkerboard pattern was tested. The flow appeared to develop much slower in each section than over a single parallel (infinitely long) roughness. The maximum velocity remains close to the smooth-to-rough interface and no secondary flow is observed in this configuration. Turbulent mixing is neither very effective since the vortices are changing direction not before 1 meter after a roughness change. Nevertheless, the effective friction is seriously increased by this configuration; about 30% additional friction is observed in comparison with a developed parallel flow without transverse interaction. This can be explained by the large adaptation length of the flow relative to the size of the checkerboard fields. The flow velocity is relatively large over the rough fields, and slow over the smooth fields, causing the additional drag.

The deadline for the Millennium Development Goal (MDG) No. 7, to halve the world’s population without access to improved sanitation is fast approaching. Reports have shown that significant progress have been made since its first initiation in the 1990s. Unfortunately, based on the current development rate, the estimated population of the world that will have improved sanitation in 2015 will be 67%, which lags behind the target goal of 75%.
Regardless, countries, government agents, sanitation experts and health organizations worldwide are continuously cooperating together to stay on track with the MDG with the objective of improving the health of the world’s population and to achieve environmental preservation. In order to provide sanitation facilities that achieves this objective, many different types of decision-making frameworks have been developed to guide decision makers in selecting the most optimal sanitation facility that could function under local conditions. These tools have varying criteria, there are one that focuses on the technical feasibility and other assess the systems based on the incurred cost as well as the willingness to pay of the user. Models that recognizes the sensitivity of the social-cultural influence of the users have also been created. Though, difficulties may come when communities ought to be assessed and expressing findings or social phenomenon in quantified values.
In light of progressive development in the sanitation world, this research aims to participate in implementing a socio-tech assessment on sanitation options in Banten, Indonesia. It has been abundantly seen that sanitation options implemented in the past stopped functioning within a period after its construction. Poor operation and maintenance, lack of managerial oversight and unavailable funds are some of the issues that trigger the abandonment of these monumental sites.
The technical functionality of different sanitation options will be assessed by adopting the decision making tool developed by Malekpour (2012). Furthermore, social assessments using qualitative analysis were conducted using three different case studies to investigate the current practices of the communities and to identify their needs and requirements with the available sanitation options. The three different sanitation systems that have passed the screening stage were 1) pour flushed toilet – communal septic tank – subsurface constructed wetland; 2) pour flush toilet – communal septic tank – upflow filter; and 3) pour flush toilet – biogas digester. After sanitation options were assessed based on a probability evaluation on their performances for the criteria of exposure to health hazard, accessibility, reliability and sustainability, the sanitation option that performed the best was the option that used the pour flush-toilet connected to a communal septic tank and subsurface wetland.
Results from the social assessments showed that receptivity of a technology is greatly influenced on its fulfilment on the demands of the users. Factors found to be of dominant requirements include: maintainability, affordability, water accessibility and convenience. By combining the findings from both the technical and social assessment, this research proposes an open toilet design that have been tailored to the practices of the local users, with a squatting pour flush toilet pan (aiding local users that are classified as washers), connected to a communal septic tank and finally to a constructed wetland with subsurface flow. This design aims to attain acceptability from the users, to motivate optimal usage of the facility and achieve health and environmental improvement in the project area of Banten, Indonesia.

Introduction
Dutch municipalities have a legal duty in groundwater management. Adequate and effective management of horizontal subsurface drainage systems is important in fulfilling this duty. The service life time of these systems have to be optimized. Financial resources should be used efficiently.
Only since a few years there is a proactive attitude towards management and maintenance of subsurface drainage systems. There is still little experience on how to manage and maintain urban subsurface drainage systems. Current knowledge on system behavior, failure mechanisms and effectiveness of maintenance is mainly based on research to field drainage in agricultural context. More fundamental knowledge on these topics is required in order to assess which maintenance and monitoring efforts are suitable for adequate system management.
Approach
My research focused on municipally managed, horizontal subsurface drainage systems (mainly installed in the sewer trench). System failure processes, possible locations of system failure, effectiveness of maintenance by jet-flushing and required monitoring and inspection efforts are studied. The knowledge is gained by execution of a detailed case study to two different system types located in the municipality of Utrecht. A predominantly submerged and a predominantly dry system. Past system state inspection and system behavior monitoring data are studied. Time series are analyzed with time series analyses tool Menyanthes. In the context of this research project, an extensive system behavior monitoring campaign is executed in the case systems. Furthermore, several inspection techniques including CCTV camera inspection are applied
Results
- Knowledge on failure mechanisms. The major failure mechanism observed in the case systems was the formation of ochre. Ochre contamination, a dynamic process, can lead to major problems with high groundwater tables.
- Insight in location of failure. Results from this research show that besides problems in the drain-soil interface focused on in literature, internal network clogging can also be a major driver for system failure.
- Insight in effectiveness of maintenance by jet-flushing. Jet-flushing appeared to be primary effective in removal of ochre blockages from the internal drain cross-sections. Time-scale of re-clogging is however short. Within several months, the effect can be negated.
- A possible approach in system investigation and assessment. Based on the obtained experience in inspecting and monitoring the case systems, an approach in system investigation and assessment is developed. The approach is presented in a decision tree-like scheme. The scheme can be used for the development of a management and maintenance plan for a particular system.
Recommendation for future research
This research can be considered as initiating research. New questions arose during the research. Permanently submerged (modern) subsurface drainage systems are not yet studied in detail. Some processes are not fully understood yet. Further research is therefore recommended.
Literature
Leidraad Riolering B2300, 2012. Functioneel ontwerp grondwateroverlast maatregelen (Functional design groundwater nuisance measures) Stichting RIONED, Ede

Aerobic granular sludge/Nereda technology has proven to be more beneficial compared to activated sludge systems. Until now not much research has been spend on treatment of Nereda excess sludge (NES). In this study the biodegradability of NES is investigated, combined with thermal pressure hydrolysis (TPH) as pre-treatment method and the application of an up-flow digester concept. The maximal biodegradability is estimated at 50% volatile solids (VS) (VS content of raw sludge is 80%). In a conventional CSTR digester 42% VS is converted, whereas TPH increased this to 48% (HRT=20 days). The up-flow digester performed slightly better than the conventional system: 43% VS is converted. Modelling of the CSTR systems showed to yield well fitting results; modelling of up-flow digesters yielded results which deviated a lot from the measured values.
Besides anaerobic digestion, the extraction procedure of alginate-like-exopolysaccharides (ALE) is optimized and the mutual influence of digestion and ALE extraction is researched. Extraction of ALE can be done with a lower amount of chemicals as the initial procedure. ALE seems to be slowly biodegraded during anaerobic digestion, although the amount of ALE recovered from digested sludge did not differ from undigested sludge. ALE extraction applied prior to digestion could be a synergistic hybrid, as the extraction procedure can act as a pre-treatment method to reduce sludge volume and increase biodegradability rate. The optimal combination is however not yet found.
Finally the influence of ALE-extraction method and protein content is investigated. ALE seems to contain a significant fraction of protein (20-40%), although large differences were observed between protein detection methods and ALE extraction methods.

In the Upper Citarum Basin in Java, Indonesia, the Creative Policy Generation Method was used to study the applicability of the integrated Business Model Canvas (Osterwalder, 2010) and the creation track (Gray, 2010), which is a creative, solution-focused thinking theory. The goal in the Upper Citarum Basin was to create better, safer and more sustainable living conditions for the residents in the basin. The combination of emerging physical issues (flood, erosion, sedimentation, pollution, water scarcity, uncontrolled urbanization and land subsidence), poor living conditions, poor policy execution by the government and generally inflexible, government-reliant communities have caused a degradation of the basin and thus the living conditions.
This research focuses on testing the Creative Policy Generation Method for Integrated Water Resources Management in Indonesia. The method incorporates three phases in order to devise alternative policy concepts to solve complex problems in multi-stakeholder settings. The three phases are:
• Assessment: Assessing the strengths, weaknesses, opportunities and threats to the physical, institutional and social economic aspects.
• Generation: Creating ideas for new policy concepts. These ideas will ultimately be presented in a Business Model Canvas.
• Evaluation: Evaluate the policies regarding their strategic value, risks and economical value.
During workshops in the generation phase, the issues mentioned above were discussed and alternative policy concepts were generated. This resulted in seven concept policies, which focus on creating solutions in an informal and un-structured manner. By integrating educational and social economic characteristics, the policy concepts require a lower investment and can be tested on a smaller scale. This provides the opportunity to obtain data, learn from this information, alter the concept policies and make them more effective.
From the perspective of this study, the Creative Policy Generation Method achieved positive results. It has been proven that business models and creation tracks are applicable in the field of Integrated Water Resources Management, but it has also been found that iterations are needed in the future to optimize this method.